Urban Wildlife Observation - Population Color Variation in Eastern Gray Squirrels (4DEE aligned module and course)

This field laboratory uses Loring Park in Minneapolis, Minnesota as a living classroom. Students observe and record eastern gray squirrels (Sciurus carolinensis) within assigned survey zones, categorizing individuals by fur color phenotype (typical gray, melanistic, or leucistic) and recording behaviors. The lab introduces students to the historical context of the parks squirrel population deliberately introduced by park superintendent Theodore Wirth in 1909 and uses that history as a springboard for discussing founder effects, genetic drift, and intraspecific variation. Students calculate phenotype frequencies, compare group data to class-wide totals, and address discussion questions linking observation to ecological and genetic concepts. Optional extensions guide students through designing a mark-recapture population estimate using the Lincoln-Petersen estimator, and through exploring the SquirrelMapper citizen science project as an entry point into urban evolution research. The lab is designed for an introductory undergraduate environmental science or ecology course and requires no prior fieldwork experience.